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"V"-Anchor Trench Calculator - Problem Statement
Anchorage is designed to prevent wind and water from moving under the geomembrane; it is not designed to allow geomembranes to be tensioned. The "V"-anchor design should allow pullout of the geomembrane before tension failure. This is directly reflected in the anchorage ratio:
| AR | Anchorage Ratio |
| TGM allow | Allowable geomembrane tension from ASTM D3886 |
| TAT allow | Allowable "V"-anchor tension from analytic model |
Following situations can occur:
| Anchorage Ratio > 1 | Geomembrane pull-out mode controls |
| Anchorage Ratio = 1 | Balanced Design |
| Anchorage Ratio < 1 | Geomembrane tension rupture mode controls |
| σallow | The allowable geomembrane stress |
| t | The geomembrane thickness |
| σult | The ultimate geomembrane stress, e.g., yield or break |
| TATallow | Allowable anchor trench tension |
| γAT | Soil unit weight |
| dv | Depth of the "V"-trench |
| d | Thickness of the cover soil |
| L | Embedment length |
| Lv | Length of the "V"-trench |
| i | slope of the "V" -trench |
| δL | FML / soil friction angle (below geomembrane) |
| δU | Cover soil / geomembrane friction angle (above geomembrane) |
| β | Side slope angle |
| FS | The factor of safety |
| FUσ | Shear force above geomembrane due to cover soil (for thin cover soils tensile cracking will occur and this value will then be negligible) |
| FLσ | Shear force below the geomembrane due to cover soil |
| FLT | Shear force below geomembrane due to vertical component of Tallow |
| σn | Applied normal stress from the cover soil |
"Designing with Geosynthetics". R.M. Koerner, Prentice Hall Publishing Co., Englewood Cliffs, NJ, 1998.
"Geosynthetic Design Guidance for Hazardous Waste Landfill Cells and Surface Impoundments", G. N. Richardson and R. M. Koerner, 1987.
Copyright 2001 Advanced Geotech Systems. All rights reserved.